You are what you are. Don't try to be something you are not. The best thing you can be in order to succeed* is to be yourself. In my opinion, you sound like a pretty good candidate. Perhaps there are a few things that could be tweaked, but I don't think there are any drastic changes necessary. Do not, however, sacrifice academics for extra-curriculars and/or volunteer work. And don't burn yourself out - that won't do anyone any good. Having said that, if you have the time, getting involved again with cadets could be beneficial.
If it makes you feel better, I am a UofT grad (Scarborough as well), but my GPA was considerably less than yours and I was not in an honours program. My only extra-curriculars prior to enrolling in ROTP were sports (generally one at a time), cadets and the Reserve (again, not both at the same time. I never had a part-time job (only full-time jobs in the summer) before ROTP. In fact, I only ever needed a part-time job AFTER I got into ROTP (the pay really sucked then - still does I believe) ;D. Mind you, I graduated over 25 years ago and getting into the CF then does not seem to have been as tough as it is today (there were still waiting lists though).
*I consider success to include happiness, a positive outlook and individual fulfillment. These things do not necessarily lead to higher rank and pay. In fact, I have made some choices over the years that have actually held me back, but which I don't regret for one moment. They were the right choices for me at the time. I have not progressed in rank at the same rate as some of my peers, but I am still married to my first wife (of over 20 years), my children still talk to me and I live a pretty comfortable life nevertheless. The best part is that my higher-ranked peers who were my friends when we were all sub-lieutenants are still my friends now.